Twelve hour scatter corrective mechanism for electric clock systems



Aug. 14, 1962 A. l. BIORGE 3,048,964

TwELvE HOUR SCATTER coRREcTIvE M ANIsM FOR ELEC EM 9 TRIO CLOCK SYST Filed Jan. 2l. 195 2 Sheets-Sheet 1 '20 /J- fil-I' FIG FIG2 FIG3 FIG4 F|G5 FIGG Aug. 14, 1962 A. l. BIORGE 3,048,964

TWELVE HOUR SCATTER CORRECTIVE MECHANISM FOR EL ECTRIC CLOCK SYSTEMS Filed Jan. 2l. 1959 2 Sheets-Sheet 2 INVENTOR. ALFRED l. BIORGE ATTORNEYS United States Patent Oice 3,048,964 Patented Aug. 14, 1962 3,048,964 TWELVE HUR SCATTER CURRECTlVE MECHA- NISM FOR ELECTRC CLOCK SYSTEMS Alfred I. Biorge, Salt Lake City, Utah, assignor to General Time Corporation, New York, NY., a corporation of Delaware Filed Jan. 21, 1959, Ser. No. 788,980 16 Claims. (Cl. 58--24) This invention relates to scatter corrective mechanisms for electric clock systems used in schools and other institutions, oflice buildings, hotels, industrial establishments, etc.

Clock systems of the type concerned include individual electric clocks positioned at desired locations throughout a building. Such clocks are electrically interconnected for synchronization from a master station, which exercises control in response to either automatic or manual supervision.

Due to power interruptions, mechanical misadjustments or wear, and various other factors, the individual clocks are su-bject to variations in time indications which are indiscriminately scattered throughout the system. If the variations between the individual clocks are less than an hour in extent, they are corrected each hour by mechanism with which all clock systems are equipped. Variations more than an hour in extent require special, socalled twelve hour, scatter corrective mechanism.

Most of the major clock systems presently available commercially utilize clock movements having a single motor. These systems are equipped with satisfactory twelve hour scatter corrective mechanisms. They are systems, however, which utilize dual-motor clock movements. No twelve hour scatter corrective device heretofore known is applicable to such a movement.

A principal object of this invention is to provide a twelve hour scatter corrective mechanism for a dualmotor clock movement.

A peculiar characteristic of a dual-motor clock movement is that a so-called re-set motor, additional to the normal drive motor, is employed to periodically advance the clock at greater than normal speed.

It does this following the transfer to it of the power from the normal drive motor by either automatic or manual means. Various ways of advancing the clock at greater than normal speed by means of the additional or re-set motor are employed for the normal hourly corrections, depending upon the particular make of clock movement.

In one type of dual-motor clock movement, disclosed in United States Patent No. 2,662,367, issued December l5, 1953, to G. L. Riggs, Ir., and assigned on its face to the Standard Electric Time Company of Springfield, Massachusetts, and as illustrated in FIGURE 13 of this application and FIGURE A of said patent, a cam r0- tated by the re-set motor is utilized to intermittently actuate a pawl 122 operative on a ratchet wheel 64 of the clock-advancing mechanism, the ratchet wheel 64 being provided with an open segment 90l for clocksynchronizing purposes. When the pawl 122 drops into the open segment 90, it rides idly and thereby prevents advance of the clock beyond a predetermined synchronizing time indication. The system provides for this synchronizing action hourly, correcting all clocks which are up to 59 minutes slow. Clocks more than 59 minutes slow will remain slow by even hours, `and such scattering will continue until each clock is individually corrected by hand.

Other `dual-motor clock movements provide for periodic engagement of the normal clock-advancing mechanism by the reset motor in various ways for advancing the clock at greater than normal speed.

In all these different types of dual-motor clock movements, the normal drive motor is shut off and is not operating while the re-set motor acts to advance the clock at an abnormally rapid rate.

Referring now to FIGURE l of the present application and FIGURE 6 of the aforementioned Riggs patent, this is accomplished by providing a master clock M connected to power lines 14S. The master clock has a motor 140. The master `clock M is arranged so that once each hour, as determined by master 1clock motor 140, switch 141 which normally connects the drive m0- tors 2.6 of the secondary clocks 21-25 to the power lines 14S through conductors 146, 154 and contacts 142 of switch 141 reverses so that the reset motors 20 of the secondary clocks 21-25 are connected to the power lines 14S through conductor 154, contacts 144, conductors 152, and 146. Thus, as described in the Riggs patent, the secondary clock mechanism 21 (FIGURE 13) will be driven .to a predetermined minute indication.

A feature of this invention is the routing of energizing current to the re-set motors of the several clocks of the system at twelve hour intervals for a predetermined synchronizing period while the clock drive motor is operating normally, and the provision of means for preventing abnormally fast re-set advance of such clocks if they are at or when they reach a predetermined correct time indication `during such synchronizing period.

rFhe re-set advance preventing means for each clock movement includes a trip member rigidly carried by the twelve hour (hour hand motivating) wheel at a predetermined position thereon and a trippable member eX- tending into the path of movement of such trip member and operable, when tripped, upon control means adapted to prevent abnormal re-setting advance of the clock.

In preferred embodiments, the control means with which the trippable member is associated takes the form of either a normally closed switch controlling the supply of current to the re-set motor, so as to open such switch when tripped, or of a mechanical arrangement operative, when tripped, to disengage the drive 'between the re-set motor and the normal clock-advancing mechanism.

Further objects and features of the invention will become apparent from the following `detailed description of the preferred speciiic constructions illustrated by way of example in the accompanying drawings.

In the drawings:

EIG. l is a wiring diagram showing how the individual clocks and the master control station of an otherwise standard clock system are electrically hooked-up yfor the purpose of twelve hour scatter correction in accordance with the invention;

FIGS. 2, 3, 4, 5, and 6 are each made up of front elevations of the time-indicating faces of the tive individual clocks of the clock system of FIG. 1, .the several views being taken at respectively different times during and subsequent to the twelve hour correction period, FIGS. 2-5 each sho-wing scattered time indications from the beginning of the correction period to the end and FIG. 6 showing the iinally synchronized time indications resulting from the immediately subsequent, normal, hourly correction;

FIG. 7 represents a front elevation of the movement of an individual clock of the system of FIG. l constructed in accordance with a form of the invention which utilizes a miniature electrical switch as the control means for preventing abnormal re-setting advance of the clock, the movement being shown at a time indicating position which is immediately prior to the commencement of the clocksynchronizing correction period;

FIG. 8 is a view corresponding to that of FIG. 7, but showing only significant parts of the movement at a timeepesses- 3 indicating and switch-opening position which is substantially maintained throughout the clock-synchronizing correction period;

FIG. 9 is a similar view showing such parts of the movement at a time-indicating and switch-closing position immediately following the clock-synchronizing correction period;

FIG. l represents a front elevation of the movement of an individual clock of the system of FIG. 1 constructed in accordance with a form of the invention which utilizes, as the control means, a mechanical arrangement for disengaging a conventional ty-pe of mechanical drive between the re-set lmotor and the normal clock-advancing mechanism, the time indicating position corresponding to that of FIG. 7;

FIG. 11 is a View corresponding to that of FIG. l0, but in which the parts shown and the time-indicating positions thereof correspond to- FIG. 8;

FIG. 12 is a similar view in which the time-indicating position corresponds to that of FIG. 9; and

FIGURE 13 is a perspective view of secondary clock mechanism according to the above cited Riggs patent and as modied according to this invention.

Referring to the drawings:

The twelve hour scatter corrective mechanism of this invention may be applied to any of the conventional `clock systems utilizing ldual motor clock movements. Regardless of the particular system, the electrical hook-up for the purposes of the invention will be as indicated in FIG. 1. There, automatic supervision is exercised at the usual master clock provided with components according to this invention enclosed by the broken line 15. Should it be desired to supervise the system manually, only the manual switch circuit 16 need be provided, this being operated on an exact time schedule conforming to that arranged for the twelve hour synchronization period in automatic supervision.

The special master clock components enclosed by broken line 15 comprise a twelve hour switch 17 arranged to be closed for an extended period short of an hour, e.g. for iifty minutes, once every twelve hours. Consider-ing the construction of conventional clock movements, this must be within the time period from :00 to 7 :00 oclock, preferably from 5:00 to 5:50 oclock. Included, also, in series circuit with the switch 17, is a timer-controlled switch 18 arranged to be closed `for something in excess of twelve minutes each hour, preferably shortly after the hour, esg. fourteen minutes, for -a period of say sixteen minutes. A normally open relay 19 ythe operating coil of which is in series circuit with these time-controlled switches 17 and 18 controls the supply of current from a suitable source of electricity, e.g. the standard 120 volt lines 148 indicated, to the re set motors 20 of the respective clocks 21-25. Thus, when both switches 17 and 18 are closed, relay 19 is energized to closed position, which routes energizing current to re-set motors 20 of the several clocks of the system.

It can be seen from the hook-up indicated that during 12hour scatter correction according to the present invention the normal drive motors 26 of the respective clocks 21-25 continue to be energized during the times that the re-set motors 20 are energized. The carrying out of ytwelve hour corrections under such circumstances is a significant `feature of the invention.

The clock movements of all the individual clocks 21-25 are identical. Each is provided with some conventional means (e.g., as sho-wn in FIGURE 13) for correcting the time indication hourly in response to hourly energizations of the re-set motor by transfer of switch 141 of the rnaster clock M. Such means are merely incidentxl 7 to this invention, and, while they should be provided is order to obtain complete twelve hour correction, the'r construction and the manner in which they are provide have nothing to do with the operation of the mechanism ot this invention.

Cil

Besides the normal drive motor 26 and the reset motor 20, each clock movement has the customary twelve hour wheel 27, FIGS. 7-13, which motivates the hour hand 12 of the clock, see FIGS. 2-6. In accordance with the invention, the twelve hour wheel 27 carries a trip member, here shown as a pin 23, rigidly projecting from the front face of the wheel near its rim.

As mentioned hereinbefore, the mechanism of the invention also comprises means for controlling the re-set advance of the clock through the conventional drive interconnecting the re-set motor with the clock-advancing mechanism, and a trippable member extending into the path of movement of the trip member and associated with such re-set advance control means, for causing the latter to prevent re-set advance of the clock when tripped. Also as mentioned hereinbefore, such control means may take dierent forms, including a miniature switch `for interrupting the supply of current to the re-set motor and a mechanical arrangement for disengaging the drive between re-set motor and clock-advancing mechanism.

The clock movement shown in FIGS. 7-9 and 13 utilizes a normally closed, miniature switch 29 as the control means. A switch-actuating arm 30, pivoted at 31 and extending into the path of movement of pin 28 to be 5 tripped as rotation of the twelve hour wheel 27 brings such pin into pushing Contact therewith, constitutes the trippable member.

In this embodiment, the re-set motor may be connected in drive relationship with the clock-actuating mechanism in any suitable manner.

The clock movement shown in FIGS. 10-12 and 13 represents a particular commercial type manufactured by the Standard Electric Time Company, the assignee of the said Riggs Patent No. 2,662,367 wherein the re-set motor and clock-advancing mechanism (FIGURE 13) are interconnected by a mechanical drive arrangement, which includes a rocker arm 32 pivoted at 33 and rocked back and forth by a pair of cam members 34a extending oppositely from a rotor 34 and operative upon an idler 32a. Such rotor 34 is secured to the output shaft 35a of a speed reducer 35, which is driven by re-set motor 20. The pivoted end of rocker arm 32 is rigidly connected to a lever arm carrying a pawl 122 (FIGURE 13) operative upon a ratchet wheel 64 component to the clock-advancing mechanism, `all of which is standard and none of which constitutes a part of this invention.

The control means of the embodiment of the invention shown in FIGURES 10-12 constitutes a lever arm 36 rigidly secured to rocker arm. 32 intermediate the ends thereof and having a hooked end providing a finger 36a which constitutes the trippable member extending into the path of movement of pin 28. When pin 28 trips the finger 36a of lever arm 36 and thereby raises such lever arm, rocker arm 32 is also raised so that its idler 32a is lifted clear of rotating cam members 34a and re-set motor 20 is no longer permitted to drive the clock-advancing mechanism.

With a clock system arranged to commence its scatter correction, clock synchronizing action, at 5:14 oclock, am. and pm., pin 28 of each clock movement will be rapidly advanced until it comes into contact with switch-actuating arm or the finger 36a of lever arm 36, see FIGS. 7 and 10, respectively, as the particular clock reaches a time indication of 5:12 oclock. By 5:14 oclock, it will have opened re-set control switch 29 or raised re-set control arm 36 to either de-energize the re-set motor 20 or disengage its drive connection with the clock-advancing mechanism, see FIGS. 8 and ll, respectively. In either event, the abnormal, rapid advance of the clock will be halted. This condition will prevail for the next sixteen minutes, it being realized that during this time the clock will be advanced at the normal relatively slow rate by reason of the continued operation of the normal drive motor 26. Thus, at 5:30 oclock, pin 28 will clear the trippable member, 30 or 36a as the case may be, and the re-set arrangement, including control means 29 or 36, will be restored to normal condition, see FIGS. 9 and 12, respectively. But the clocks will not resume the abnormal rapid advance, because timer-controlled switch 18 at the master clock will be opened at 5:30 oclock to cut ofi flow of current to the re-set motors.

The re-set means are advantageously arranged to advance the clock one full hour each minute of operation. Thus, a clock three hours slow, for example, will be three minutes slow at the completion of the twelve hour scatter corrective operation in accordance with this invention due -to the three minutes required for the correction; but such discrepancy in time indication will be corrected by the next hourly correction carried out in conventional manner by the conventional mechanism provided for the purpose, as referred to hereinbefore.

This is clearly shown by the sequence of time indications of the several individual clocks 21-25 of the sys- -tem during and immediately after a twelve hour correction period, as illustrated in FIGS. 2-6. In FIG. 2, the two lower clocks 24 and 25 ofthe syste-m correctly indicate the H time as 5:14 oclock at the start of the correction period. Clock 21 incorrectly indicates the time as 1:00' oclock, and is, therefore, four hours and fourteen minutes slow. Clock 22 incorrectly indicates the time as 9:00 oclock, and is, therefore, eight hours and fourteen minutes slow. Clock 23 incorrectly indicates the time as 3:00 oclock, -being two hours and fourteen minutes slow.

Six minutes later, as shown in FIG. 3, clocks 24 and 25 indicate the correct time of 5:20 oclock, because they have been operating normally. Clock 21 is four minutes slow, incorrectly indicating the time as 5: 16 oclock. This is due to the one minute consumed by the correction or synchronizing operation for each hour corrected. When clock 21 reached the 5:14 oclock time indication, which stopped the correction or synchronizing operation, it was four minutes slow. For the next two minutes of the six that passed between the showings of FIGS. 2 and 3, it operated normally. Clock 22 has been corrected to the extent of six hours, so that it now incorrectly indicates the time vas 3:00 oclock, Thus it is now only two hours and twenty minutes slow, having lost six minutes during the correction or synchronizing operation. Clock 23 has been entirely corrected, hourwise but, because it lost two minutes during the correction or synchronizing operation, it now indicates the time incorrectly as 5: 18 oclock,

At 5 :30 oclock, the end of the sixteen minute correction or synchronizing period, the two lower clocks 24 and 25 still show the correct time of 5:30. The upper clock 21 is still four minutes slow, incorrectly indicating the time as 5:26 oclock. Clock 22 reached its 5:14 oclock time indication eight minutes after the beginning of the period, and, therefore, lost eight minutes dueto the correction or synchronizing operation. It now incorrectly shows the time at 5:22 oclock. Clock 23 is still two minutes slow, indicating the time incorrectly as 5:28 oclock.

At 5:45 oclock, the two lower clocks 24 and 25 are still correct, while the three upper clocks 21, 22 and 23 are still slow by four, eight, and two minutes, respectively, indicating the time incorrectly as 5:41, 5:37, and 5:43 oclock, respectively.

At 6:00 oclock, however, the conventional hourly correction mechanism brings about the final correction or synchronizing of the several clocks, so that all indicate the correct time as shown in FIG. 6.

Whereas this invention is here illustrated and described with particular reference to presently preferred specific forms thereof, it should be understood that various changes may be made in such forms and various other forms may be constructed without departing from the essential concepts and teachings hereof.

I claim:

1. In a master clock system including a master clock and at least one secondary clock connected thereto and synchronized thereby, each secondary clock including a drive motor which when energized drives its secondary clock at a rate to normally maintain proper time indication, each secondary clock also including a re-set motor which when energized drives its secondary clock at a fast rate until `a predetermined minute indication is attained, the master clock including means for energizing the re set motors and de-energizing the drive motors periodically to correct the minute indications of the secondary clocks: the improvement comprising, in combination; means at said master clock for periodically energizing the re-set motors for an extended period of time while the drive motors are energized, means at each secondary clock for preventing the re-set motor from driving its secondary clock during said extended period when said secondary clock indicates a predetermined time prior to the beginning of said extended period, said extended period being less than the period of time between minute indication correction cycles of the system and terminating prior to the commencement of the next following minute indication correction.

2. The combination defined in claim 1, wherein said means at said master clock for periodically energizing the re-set motors for an extended period of time comprises a pair of series-connected switches, the iirst of said switches being closed during each interval between minute indication corrections for a period corresponding to said extended period of time, and the second of said switches being closed for the duration of the interval between the minute indication corrections immediately prior to and subsequent to said extended period of time.

3. The combination defined in claim 2 and an elec tromagnetic relay at said master clock, said relay including contacts which close a circuit to provide energization to said re-set motors when said relay is energized, the energizing coil of said relay being connected in series with said pair of switches for energization when both of said switches are closed.

4. The combination defined in claim 1 wherein each of the secondary clocks includes an hour wheel, and said means for preventing the re-set motor of each secondary clock from driving its clock comprises control means on the hour wheel at a predetermined position and cut out means actuated by said control means when the clock indicates said predetermined time.

5. The improvement of claim 4, wherein said cut out means is a normally closed electric switch interposed in the electrical supply line to the re-set motor whereby said re-set motor is deaenergized when its clock indicates said predetermined time.

6. The improvement of claim 5, wherein said control means is a pin rigidly projecting from a face of the twelve hour wheel near the rim thereof.

7. The improvement of claim 4 wherein each of the secondary clocks includes a ratchet and pawl mechanism driven by its re-set motor to drive it at the said fast rate, said improvement further defined in that said cut out means comprises an actuating arm connected to the ratchet and pawl mechanism, said actuating arm being adapted to prevent operation of said ratchet and pawl mechanism when said arm is actuated by said control means.

8. The improvement of claim 7, wherein the ratchet and pawl mechanism includes a pawl-actuating rocker arm, and means driven by the re-set motor for rocking said arm, said improvement further defined in that said actuating arm is connected with the rocker arm and moves it out of range of said rocking means when said actuating arm is moved by said control means.

9. The improvement of claim 8, wherein said control means is a. pin rigidly projecting from a face of the twelve hour wheel near the rim thereof.

10. The improvement of claim 9, wherein said actuating arm is rigidly aiixed directly to said rocker arm intermediate the length of the latter.

11. In a master clock including means for energizing a drive circuit, and means for periodically de-energizing the drive circuit and energizing a reaset circuit to ecect minute synchronization of a plurality of secondary clocks connected to the drive and re-set circuits: the improvement comprising hour synchronization means for periodically energizing the re-set circuit for an extended period of time while the drive circuit is energized, said eX- tended period being greater than that required for minute synchronization.

12. The improvement of claim 11 further defined in that said hour synchronization means energizes the re-set circuit for a period of time at least equal to the number of hours between said periods multiplied by the time in minutes that the re-set circuit is required to be energized to effect minute synchronization.

13. The improvement of claim 11 in a master clock which eiects minute synchronization once each hour during substantially la one minute period; said improvement further defined in that said hour synchronization means ener-gizes the re-set circuit once every twelve hours for a period of at least twelve minutes while the drive circuit remains energized.

14. In a secondary clock mechanism including a drive circuit and a reset circuit, an electrically powered drive means connected to the drive circuit for driving the clock at a normal rate to maintain proper time indications, an electrically powered reset means connected to the reset circuit -rfor dri-ving the clock at an accelerated rate until a predetermined minute indication is attained, the secondary clock mechanism including an hour wheel; the improvement providing `for hour scatter correction upon simultaneous energiza-tion of the drive and reset circuits comprising, in combination, a normally closed switch connected in said reset circuit in series with said reset means, and switch actuating means mounted at a predetermined position on the hour wheel, said switch actuating means opening said norm-ally closed switch for an indicated E; period of time less than the period of time between said predetermined minute indications, and said indicated period terminating prior to one of said predetermined minute indications.

15. In a -secondary clock mechanism including a drive motor which when energized drives the clock at a normal rate to maintain proper time indication, a reset motor, a mechanical linkage normally engaged with the reset motor and the clock mechanism for driving the clock mechanism at an accelerated rate until a predetermined 4minute indication is attained when the reset motor is er1- ergized, lthe clock mechanism including an hour wheel; the improvement providing for hour correction upon `simultaneous energization of the drive and reset motors comprising, in combination, means for disengaging the mechanical link-age from the reset motor yfor an indicated period of -time less than the period of time between said predetermined minute indications and terminating prior to one of said predetermined minute indications, and actuating means mounted on the hour wheel controlling the operation of said disengaging means.

16. The combination defined in claim 15 in `a sec ondary clock mechanism wherein the mechanical linkage includes a cam driven by the reset motor and a cam follower driven by said cam, said disengaging means comprising means connected `to said cam follower for disengaging the cam follower from the cam.

References Cited in the le of this patent UNITED STATES PATENTS 2,026,368 Warren Dec. 31, 1935 2,447,798 Deane Aug. 24, 1948 2,724,232 Stoddard et al Nov. 22, 1955 2,724,233 Cole Nov. 22, 1955 2,900,787 Blouin Aug. 25, 1959 

